One-way clutch

ABSTRACT

A one-way clutch includes a retainer ( 3 ), a spring ( 4 ) guided by the retainer, and sprags ( 5 ) which are pivotally provided in respective pockets of the retainer and respective pockets of the spring. A rounded section ( 4   c ) is formed on an outer diameter side of each of tongue-like flaps ( 4   t ) of the spring. Guide sections ( 3   c,    3   c ) are formed at respective corners on one side of each pocket with respect to a circumferential direction thereof. The width (D) of a space between the guide sections is set so as to become greater than the width (T) of each of the tongue-like flaps formed in the spring, and the rounded section ( 4   c ) is housed in the space between the guide sections.

BACKGROUND OF THE INVENTION

The invention relates to a one-way clutch, and more particularly, to aone-way clutch in which tongue-like flaps of a spring provided on aninner diameter side of a retainer do not interfere with portions ofsprags or portions of the retainer and are made greater in strength, tothereby improve engagement performance.

A one-way clutch used in an automatic transmission of an automobile isinterposed between outer and inner rings, and transmission andinterruption of power is effected repeatedly. As shown in FIG. 9, such aone-way clutch is usually constituted by sprags 15, a retainer 13, and aspring 14, and is placed in an annular space 20 defined between an outerring 11 and an inner ring 12. When the one-way clutch is rotated in onedirection at the time of transmission of power, by means of relativerotation between the outer ring 11 and the inner ring 12, the sprags 15act as wedges, whereby the outer ring 11 and the inner ring 12 rotate inan integrated fashion (a locked state). When the retainer 13 is rotatedin the opposite direction, the sprags 15 are released from a wedge-likestate and perform idle running, thereby interrupting power transmission(an unlocked state). In some cases the retainer consists of tworetainers; that is, an outer retainer and an inner retainer. The tworetainers are rotated relatively under a locked state and under anunlocked state.

In such a one-way clutch of sprag type, the spring 14 is guided along aninner diameter side of the retainer 13, thereby enabling correct radialpositioning of the sprags 15 retained by the spring 14. Tongue-likeflaps 14 of the spring 14 usually impart pre-stress (i.e., force) to thesprags 15 toward a direction in which the sprags 15 are to be locked,thus contributing to an engagement characteristic. As mentioned, thetongue-like flaps 14 t become deformed, as occasion demands, throughrepeated idle running and engaging actions of the sprags 15. For thisreason, the tongue-like flaps that impart pre-stress to the sprags 15are subjected to repeated stress. In many cases, each of the tongue-likeflaps is provided with a rounded section for enhancing the rigiditythereof.

As indicated by chain double-dashed lines shown in FIG. 9, when arounded section 14 a of the tongue-like flap 14 t of the spring isoriented outward, the rounded section 14 a may interfere with the innerdiameter side of the retainer 13, because the spring is usually guidedtoward the inner diameter side of the retainer 13. When the sprags aresubjected to maximum inclination; for example, in the case that thetongue-like flaps 14 t of the spring are provided respectively with theoutward-oriented rounded sections 14 a or that excessive decentering hasarisen between the outer and inner rings, only the extremities of thetongue-like flaps 14 t fail to act on the sprags, and the roundedsections 14 a interfere with the sprags 15. As a result, the tongue-likeflaps 14 t fail to exhibit appropriate spring force, therebydeteriorating the engagement characteristic.

FIG. 10 shows the configuration of a related-art one-way clutch. Asillustrated, with a view to addressing repeated stress, rounded sections24 a are formed on radially inner-diameter sides of respectivetongue-like flaps 24 t of a spring 24 provided along an inner diameterside of a retainer 23, to thereby enhance rigidity of the tongue-likeflaps 24 t. When the rounded sections 24 a oriented toward an innerdiameter are provided, as in the case of the tongue-like flaps 24 t ofthe spring 24, there is apprehension that the rounded sections 24 a mayinterfere with the adjacent sprags 25 at the time of idle runningoperation. Hence, large rounded sections cannot be provided.

FIG. 11 shows a one-way clutch constituted by a retainer 23 having aflange section 23 f, a spring 24, and sprags 25.

In such a one-way clutch, the retainer 23 and the outer ring are rotatedsynchronously. Hence, in many cases, the retainer 23 is fitted into anouter ring (not shown) while being given interference allowance. To thisend, an outer diameter of the retainer 23 (i.e., an outer diameter ofthe flange 23 f) is made slightly larger than the inner diameter of atrack surface of the outer ring, whereby the retainer 23 is press-fittedto the outer ring. Thus, there is provided a one-way clutch impartedfixing force. By the pressure required when the retainer 23 ispress-fitted into an inner peripheral surface of the outer ring, theretainer 23 becomes eccentricity with respect to the outer ring, therebyrendering clearance between the sprags 25 and the pockets of theretainer 23 narrow. In order to avoid such a problem, there has beenproposed a method of forming notches 23 c in the flange 23 f of theretainer 23 at uniform intervals with reference to a circumferentialdirection so as to divide the flange 23 f into pieces of equal parts (asdescribed in Japanese Utility Model Publication No. 43370/1994).Alternatively, a slightly-oval retainer is fixedly pressed into an outerring such that the outer ring operates along with the retainer in anintegrated fashion (Japanese Utility Model Publication No. 10233/1994).

As shown in FIG. 9, the spring 14 is provided on the internal diameterside of the retainer 13 for retaining the sprags 15. Tongue-like flaps14 t of the spring 14 force the sprags 15, at all times, toward adirection in which the sprags 15 are to be locked. Since the retainer 13is to be operated in synchronism with the outer ring 11, when theretainer 13 of slightly ellipse shape is press-fitted into the innerperipheral surface (i.e., track surface) of the outer ring 11, thespring 14 becomes locally deformed toward the radial center because of,particularly, reaction force stemming from press-fitting of the ellipseportion of the retainer 13. Therefore, the force exerted on the sprags15 by the tongue-like flaps 14 t of the spring 14 which impartspre-stress to the sprags 15 is weakened by the local deformation of thespring 14. In areas where the spring 14 is deformed to a great extent,the attitude of the sprags 15 is inclined heavily toward the directionof idle running. When the sprags 15 move from an idle running positionto an engagement position, the amount of deformation of the tongue-likeflaps 14 t of the spring 14 becomes greater, thereby rendering thetongue-like flaps 14 t easy to break. Such breakage in turn induces anengagement failure in a one-way clutch.

SUMMARY OF THE INVENTION

The invention has been conceived to address the foregoing problem andobject of the invention it to provide a one-way clutch which preventsrounded sections provided on respective tongue-like flaps of a spring,the flaps imparting pre-stress (force) to the sprags, from interferingwith a retainer or the sprags and which achieves a superior engagementcharacteristic and involves very little fear of deformation andfracture.

Another object is to provide a one-way clutch which, even wheninterference allowance to be ensured between a retainer and an outerring becomes large, maintains appropriate spring force, ensuressynchronism between the outer ring and the retainer without weakeningspring force of tongue-like flaps, and does not entail a cost hike.

In order to solve the aforesaid object, the invention is characterizedby having the following arrangement.

-   -   (1) A one-way clutch comprising:        -   an annular retainer including,            -   a plurality of first pockets, and            -   a pair of guide sections formed at opposite corners on                one side of each first pocket with respect to a                circumferential direction thereof, and defining a space                therebetween having a first width;        -   a spring guided by an inner surface of the retainer,            including,            -   a plurality of second pockets,            -   a plurality of tongue-like flaps projecting to the                plurality of second pockets, respectively, and            -   a plurality of rounded sections, each of which is formed                on the tongue-like flap, projects toward the retainer                and has a width smaller than the first width, wherein                the rounded section is interposed between the pair of                guide sections; and        -   a plurality of sprags pivotally provided in the plurality of            first and second pockets and forced toward a direction in            which the sprag is to be locked by the plurality of            tongue-like flaps, respectively.    -   (2) The one-way clutch according to (1), wherein each of the        plurality of sprags includes a recessed section formed on a side        thereof which comes into contact with a corresponding        tongue-like flap for preventing interference between the sprag        and the rounded section when the sprag is inclined with a        maximum angle.    -   (3) The one-way clutch according to (1), wherein the spring        includes a pair of annular sections and a plurality of coupling        sections interconnecting the pair of annular sections so as to        define the plurality of second pockets.    -   (4) The one-way clutch according to (3), where in the plurality        of tongue-like flaps project from the plurality of coupling        sections, respectively.    -   (5) The one-way clutch according to (1), wherein one end and the        other end of the spring are superposed each other to form an        annular shape.    -   (6) The one-way clutch according to (5), wherein the second        pockets disposed on each of the one end and the other end of the        spring are superposed each other.    -   (7) An one-way clutch comprising:        -   an annular retainer including a plurality of pockets and            fitted into an outer ring in a state that reaction force of            the retainer acting on the outer ring is uneven;        -   a spring including a plurality of pockets and provided along            an inner side of the retainer so that a portion of the            spring where the reaction force of the retainer becomes            maximum is made greater in rigidity than the remaining            portion of the spring; and        -   a plurality of sprags provided in the plurality of pockets            of the retainer and the spring.    -   (8) The one-way clutch according to (7), wherein the portion of        the spring where the reaction force of the retainer becomes        maximum is made greater in rigidity by superposing one end of        the spring on the other end of the spring.    -   (9) The one-way clutch according to (8), wherein the pocket        disposed on each of the one end and the other end of the spring        are superposed each other.    -   (10) The one-way clutch according to (7), wherein the portion of        the spring where the reaction force of the retainer becomes        maximum is made greater in rigidity than the remaining portion        of the spring by hardening.    -   (11) The one-way clutch according to (7), wherein        -   the retainer includes an ellipse flange section fitted into            the outer ring, and        -   the portion of the spring where the reaction force of the            retainer becomes maximum corresponds a portion of the            ellipse flange section at a maximum diameter.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a view showing the configuration of a one-way clutchaccording to the invention; that is, a fragmentary cross-sectional viewof the clutch when viewed in the direction orthogonal to an axialdirection;

FIG. 1B is an enlarged view of a section P shown in FIG. 1A;

FIG. 2A is a fragmentary plan view of a retainer constituting theone-way clutch and a spring guided by the retainer;

FIG. 2B is a cross-sectional side view of the retainer and the spring;

FIG. 3 is a fragmentary perspective view of the spring constituting theone-way clutch of the invention;

FIG. 4 is a side view of a one-way clutch according to the invention;

FIG. 5 is a cross-sectional view of the one-way clutch of the inventionwhen viewed along line A—A shown in FIG. 4;

FIG. 6 is an enlarged cross-sectional view of section P shown in FIG. 4,showing the one-way clutch of the invention;

FIG. 7 is an enlarged view of a ribbon spring section constituting theone-way clutch for describing an overlap;

FIG. 8 is an overall perspective view of the ribbon spring constitutingthe one-way clutch of the invention;

FIG. 9 is a view showing the configuration of a related-art one-wayclutch;

FIG. 10 is a view showing another configuration of a related-art one-wayclutch; and

FIG. 11 is an example side view of the related-art one-way clutch.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A specific embodiment of the invention will be described hereinbelow byreference to the drawings.

First Embodiment

FIG. 1A is a view showing the configuration of a one-way clutchaccording to the invention. The view is a fragmentary cross-sectionalview of the clutch when viewed in the direction orthogonal to an axialdirection. FIG. 1B is an enlarged view of a section P shown in FIG. 1A.FIG. 2A is a fragmentary plan view of a retainer and a spring, whichconstitute the one-way clutch. FIG. 2B is a side cross-sectional view ofthe retainer and the spring. FIG. 3 is a perspective view of the spring.The one-way clutch is constituted by the retainer 3, the spring 4provided on the inner diameter side of the retainer 3, and the sprags 5provided in the respective pockets defined between the retainer 3 andthe spring 4. The one-way clutch is disposed in an annular space 10defined between an outer ring 1 and an inner ring 2 and causes the outerring 1 to engage with or disengage from the inner ring 2. As shown inFIG. 2B, a solid line designates a state in which the spring 4 does notretain the sprags 5, and a chain double-dashed line designates a statein which the spring 4 retains the sprags 5.

Annular sections 3 a are formed on opposite sides of the retainer 3,respectively. Coupling sections (rung sections) 3 b are formed atuniform intervals in a circumferential direction between the annularsections 3 a. Pockets 3 p are formed between the annular sections 3 aand the rung sections 3 b, and the sprags 5 are provided in therespective pockets 3 p. The spring 4 is guided along the inner diameterside of the retainer 3.

Holes of the pockets 3 p are formed in the retainer 3, and each holeassumes a convex profile when viewed in cross section (i.e., an uppercenter of each pocket projects upward so that step portions are providedon opposite sides of the pocket). As will be described later, bothcorners at one end of each pocket 3 p of the retainer 3 with respect toa circumferential direction thereof; that is, convex steps (3 c, 3 c)act as guide sections (hereinafter called “guide sections 3 c”) forguiding the spring 4 by placing each tongue-like flap 4 t of the springin the space between the steps.

Annular sections 4 a are formed on opposite sides of the spring 4,respectively. Coupling sections 4 b are formed at uniform intervals in acircumferential direction between the annular sections 4 a. Pockets 4 pare defined between the annular sections 4 a and the rung sections 4 b.The sprags 5 are placed in the pockets 4 p, respectively. In otherwords, the retainer 3 and the spring 4 are substantially overlapped,that is, the annular section 3 a and the annular section 4 a aresubstantially overlapped, the rung section 3 b and the rung sections 4 bare substantially overlapped, and the pocket sections 3 p and the pocketsections 4 p are substantially overlapped. As mentioned above, thepockets 3 p of the retainer 3 are each formed so as to assume the convexprofile when viewed in cross section. In contrast, the pockets 4 p ofthe spring 4 are each formed so as to assume a concave profile whenviewed in cross section (i.e., an upper center of each pocket isprojected downward, and steps are provided on both sides of the pocket).The portion of the spring 4 projecting downward in the concave holecorresponds to the tongue-like flap 4 t. The tongue-like flaps 4 t exertforce to the sprags 5 placed in the pockets 3 p, 4 p.

As is evident from FIGS. 2A and 2B, the tongue-like flap 4 t of thespring 4 is located between the guide sections 3 c, 3 c of the hole ofthe pocket 3 p of the retainer 3 (i.e., in the transverse center of thepocket 3 p). In this case, the space between the guide sections 3 c ofthe pocket 3 p of the retainer 3 is set so as to become wider than thewidth T of the tongue-like flap 4 t of the spring 4. Specifically, theretainer 3 guides the spring 4 while bringing the spring 4 insubstantially intimate contact with the inner diameter side of theretainer 3. In this case, the tongue-like flaps 4 t of the spring 4 areplaced in the spaces defined between the guides 3 c of the respectivepockets 3 p, thereby guiding the spring 4. A rounded section 4 c isformed on an outer-diameter exterior side of each tongue-like flap 4 tof the spring 4. By means of the rounded section 4 c, the tongue-likeflap 4 t is given larger flexural rigidity and higher strength againstfatigue or fracture.

An extremity 4 e of each tongue-like flap 4 t of the spring 4 isslightly rounded. When the sprays 5 are placed in the respective pockets4 p of the spring 4, the extremities 4 e of the tongue-like flaps 4 tare brought into contact with smooth recessed sections 5 d which will bedescribed later and are formed in positions of the sprags 5 close totheir inner diameters, thereby forcing the sprags 5 toward a directionin which they are to be locked (see FIG. 1).

A smooth cam surface 5 a is formed in an outer circumferential surfaceof each sprag 5 so as to come into contact with the innercircumferential surface 1 a of the outer ring 1. A smooth cam surface 5b is formed on an inner circumferential surface of each sprag 5 so as tocome into contact with the outer circumferential surface 2 a of theinner ring 2. A recessed section 5 c is formed on the side of the sprag5 that comes into contact with the tongue-like flap 4 t of the spring 4in a cross section with respect to the direction that the sprag 5 is toundergo pivotal movement when the sprag 5 is fitted into a correspondingpocket 4 p of the spring 4. The recessed section 5 c preventsinterference between the sprag 5 and the rounded section 4 c of thetongue-like flap 4 t of the spring 4, which would otherwise be causedwhen the sprag 5 is subjected to maximum inclination. An indentation 5 dis formed in an inner diameter side of the recessed section 5 c of thesprag 5 such that smooth contact arises between the rounded portion ofthe extremity 4 e of the tongue-like flap 4 t of the spring 4 and therecessed section 5 c. A side surface 5 e of the sprag 5 opposite thesurface which comes into contact with the tongue-like flap 4 t of thespring 4 is formed into the shape of a dent such that a center ofrotation comes to an appropriate position on the sprag 5 when the sprag5 undergoes pivotal movement.

As has been described in detail, according to a one-way clutch of theinvention, a rounded section for mitigating stress is provided on atongue-like flap of a spring, the flap imparting pre-stress (or force)to a corresponding sprag. The rounded section can prevent occurrence ofinterference between the tongue-like flap and the sprag or anothermember of a retainer.

Accordingly, there can be ensured synchronism of the sprags andimprovement in the engagement characteristic of the one-way clutch.Further, the rounded section of the tongue-like flap of the spring doesnot interfere with another member, thereby preventing deformation orfracture.

Second Embodiment

FIG. 4 is a side view of a one-way clutch according to the invention;FIG. 5 is a cross-sectional view taken along line A—A shown in FIG. 4;and FIG. 6 is an enlarged cross-sectional view of a section P shown inFIG. 4. FIG. 7 is an enlarged view of a portion of the spring shown inFIG. 5 for describing an overlap; and FIG. 8 is an overall perspectiveview of a spring used in the one-way clutch of the invention.

The one-way clutch is constituted by a retainer 103, a spring (e.g., aribbon spring) 104 arranged so as to follow an inner diameter side ofthe retainer 103, and sprags 105 fitted into corresponding pockets 103 pof the retainer 103. The retainer 103 is placed in an annular space 110defined between an outer ring 101 and an inner ring 102. A flangesection 103 f is formed on one side of the retainer 103. An outercircumferential surface 103 e of the flange section 103 f ispress-fitted into an inner circumferential surface 101 a (also called atrack surface 101 a) of the outer ring 101. In order to ensurepress-fitting, a portion of the flange section 103 f is formed into anellipse shape. The following description is provided for the case wherea single retainer 103 is used. The invention can also be applied to acommonly-employed one-way clutch using two retainers; that is, an outerretainer and an inner retainer. Alternatively, flange sections may beformed on opposite sides of the retainer 103, respectively. In thiscase, one of the flanges is caused to have an outer diameter smallerthan the diameter of a small circle.

As shown in FIG. 8, the spring 104 assumes a shape substantiallyidentical with that of the retainer 103. The spring 104 comprisesannular sections 104 a constituting respective sides of the spring 104;coupling sections 104 b (rung sections) for inter connecting the annularsections 104 a at given intervals in a circumferential direction; pocketsections 104 p which are defined by the annular sections 104 a and thecoupling sections 104 b and in which sprags 105 are to be fitted,respectively; and tongue-like flaps 104 t which project from therespective coupling sections 104 b toward the corresponding pockets 104p. The spring 104 is formed by means of punching a thin metal platethrough press machining and formed into an annular shape. As will bedescribed later, portions of the edges of the annular spring 104 areoverlapped with each other, thereby increasing the rigidity of thethus-overlapped portions of the spring 104.

As mentioned above, when the flange section 103 f of the retainer 103 ispress-fitted into the track surface 101 a of the outer ring 101, an ovalportion 103 c of the retainer 103 designated by section P shown in FIG.4 is given the largest interference allowance. Therefore, the amount ofdeformation of this portion of the retainer 103 is subjected to a localincrease. In this case, the amount of deformation of the spring 104provided along the inner diameter side of the retainer 103 usuallybecomes smaller. Accordingly, the amount of deformation of thetongue-like flaps 104 t of the spring 104, the flaps forcing the sprags105 toward a side in which the sprags 105 are to be locked, becomessmaller. Hence, pre-stress exerted on the sprags 5 by the tongue-likeflaps 104 t becomes smaller. As shown in FIGS. 7 and 8, in order toprevent this situation, there is formed a partial overlap section 106where one end 104 c of the spring 104 and another end 104 d of the sameare superimposed on each other, thereby enhancing the rigidity (springforce) of the spring 104 (for the sake of explanation of the spring 104,FIG. 7 shows that one end and the other end are spaced away from eachother). In this way, when the rigidity (spring force) of the overlapbecomes greater, pre-stress to be exerted on the sprags 105 can beensured even when the amount of deformation of the ellipse portion 103 cof the retainer 103 has become greater and the amount of deformation ofthe tongue-like flaps 104 t of the spring 104 has become smaller.Consequently, the sprags 105 are prevented from being deformed greatlytoward the direction of idle running. Even when moving from an idlerunning position to an engagement position, all the sprags 105 operatesynchronously in the usual manner.

The one-way clutch of the invention prevents the sprag 105 from excessleaning toward the direction of free running due to a decrease in theforce exerted on the sprags 105 in which the force is produced bydisplacement of the retainer 103 and the tongue-like flaps 104 t of thespring 104, the displacement being caused by reaction force producedwhen the retainer 103 is press-fitted into the track surface 101 a ofthe outer ring 101, and the ellipse portion 103 c are press-fitted intothe track surface 101 a of the outer ring 101. With a view to preventingfatigue of the spring 104, which would otherwise be caused bypress-fitting of the ellipse portion 103 c of the retainer 103, aportion of the spring 104 is given a double structure, thereby enhancingthe rigidity of a portion of the spring 104. In order to enhance therigidity of a portion of the spring 104 in the manner as mentionedabove, the rigidity of the portion of the spring may be enhanced bymeans of locally changing hardening conditions (for the portion of thespring which would be subjected to greater reaction force stemming frompress-fitting action), as well as by means of imparting a doublestructure to a portion of the spring. Furthermore, the shape of aportion of the spring 4 may be changed so as to have greater rigidity.When the portion of the retainer 103 that is given the largestinterference allowance is distinguished by utilization of a marking,such as a production symbol provided at the time of press-molding, anoverlap in the spring can be fitted to an appropriate position of theretainer 103. Since the spring can be fitted into the retainer withoutinvolvement of an assembly error, the marking is convenient.

The one-way clutch according to the invention may be constituted bycombing the first embodiment to the second embodiment.

As mentioned in detail, the one-way clutch of the invention can inhibitfatigue of tongue-like flaps and prevent occurrence of an engagementfailure, by means of enhancing the spring force of the tongue-like flapsof a ribbon spring located in a position between the retainer and theouter ring, where the largest interference allowance is ensured.Further, the one-way clutch can appropriately enhance spring forcewithout involvement of a cost increase. Further, a conventional markingcan be utilized for distinguishing the position of the retainer that isgiven the largest interference allowance, thereby avoiding a costincrease.

1. An one-way clutch comprising: an annular retainer including aplurality of pockets and fitted into an outer ring in a state that areaction force of the retainer acting on the outer ring is uneven; aspring including a plurality of pockets and provided along an inner sideof the retainer so that a portion of the spring where the reaction forceof the retainer becomes maximum is made greater in rigidity than theremaining portion of the spring; and a plurality of sprags provided inthe plurality of pockets of the retainer and the spring.
 2. The one-wayclutch according to claim 1, wherein the portion of the spring where thereaction force of the retainer becomes maximum is made greater inrigidity by superposing one end of the spring on the other end of thespring.
 3. The one-way clutch according to claim 2, wherein the pocketdisposed on each of the one end and the other end of the spring aresuperposed each other.
 4. The one-way clutch according to claim 1,wherein the portion of the spring where the reaction force of theretainer becomes maximum is made greater in rigidity than the remainingportion of the spring by hardening.
 5. The one-way clutch according toclaim 1, wherein the retainer includes an ellipse flange section fittedinto the outer ring, and the portion of the spring where the reactionforce of the retainer becomes maximum corresponds to a portion of theellipse flange section at a maximum diameter.
 6. A one-way clutchcomprising: an outer ring; an annular retainer fitted inside the outerring such that a reaction force is uneven, the annular retainerincluding a plurality of pockets; a spring inside the annular retainerand having a portion with a greater rigidity at where the reaction forceof annular retainer is at a maximum than the remaining portion of thespring, and having a plurality of pockets; and a plurality of sprags inthe plurality of pockets of the annular retainer and the spring.
 7. Theclutch of claim 6, wherein the portion of the spring having a greaterrigidity comprises superposed ends of a ribbon spring.
 8. The clutch ofclaim 6, wherein the portion of the spring having a greater rigiditycomprises a portion that is harder than the remaining portion of thespring.
 9. The clutch of claim 6, wherein the retainer comprises anellipse flange section.
 10. The clutch of claim 9, wherein the portionof the spring having a greater rigidity corresponds to the position ofthe flange which has a maximum free diameter.
 11. The clutch of claim 6,further comprising an inner ring inside the spring.
 12. The clutch ofclaim 7, further comprising another retainer between the inner ring andthe outer ring.
 13. The clutch of claim 12, wherein the another retainercomprises an internal flange section having an inside diameter that isless than the outer diameter of the inner ring.
 14. The clutch of claim6, wherein the retainer comprises a marking that indicates where thereaction force is at a maximum.